Water-control structure and cladding element therefor

ABSTRACT

A water-control structure includes a control structure body ( 1 ) having at least one side ( 10, 11 ) which is exposed to the influence of a body of water ( 12 ) and adjacent cladding elements ( 3 ) which cover the control structure body ( 1 ) and which each include a base ( 6 ). The cladding elements ( 3 ) each have a free projection ( 7 ) which is upright with respect to the base ( 6 ) and are covered with a soil layer ( 5 ) which is provided between and above the projections ( 7 ).

The invention relates to a water-control structure, comprising a control structure body which is exposed, at least on one side, to the effects of a body of water, and adjacent cladding elements which cover the control structure body and which each comprise a base, and adjacent bases of the cladding elements between themselves define passages for allowing water through.

Such a water-control structure is generally known. The cladding elements which could be made, for example, from concrete, ensure that the control structure body is better protected against the effects of the water, in particular against the effects of waves. The control structure body may be made of, for example, sand, clay or mixtures thereof with hard core, and would run the danger of being swept away or eroded if it were directly exposed to water.

The base of the cladding elements is usually configured such that a certain percentage of open spaces are left between adjacent bases, so that water which has entered the control structure body is able to escape without the cladding being forced upwards from below as a result of water pressure. These open spaces may comprise a filling of, for example, hard core or gravel. This hard core results in the cladding elements performing a clamping action on each other. As a result thereof, the stability of the layer of cladding elements is increased, while the water-permeability is maintained. The upper side of the cladding elements has a shape which is adapted to the circumstances determined by the body of water, and may, for example, in particular be suitable for dissipating wave energy.

Water-control structures may be configured in various ways. By way of example, water-control structures whose free surface is formed by the top of the cladding elements are mentioned. Other water-control structures have a soil layer which determines the top surface. In the latter cases, it is very important that this soil layer is securely anchored with respect to the control structure body. It is an object of the invention to provide an improved stabilizing action for this latter type of water-control structures.

This object is achieved by the fact that the cladding elements are covered by a covering layer which is provided between and above the projections. With the water-control structure according to the invention, the covering layer, such as a soil layer, is stabilized by the fact that it is anchored on the underside by means of the projections of the cladding elements which protrude therein. As a result thereof, the covering layer is securely fixed, even when it is subjected to the effects of water currents, waves and the like. It is not readily possible to make the complete covering layer slide with the water, not even as a result of the inclined position which the soil layer often has. This retaining effect is partly due to the projections each being embedded in the covering layer around the entire periphery thereof.

Preferably, the cladding elements are configured such that they have one and only one projection which is upright with respect to the base. As a result thereof, the production is facilitated. The projections may be completely embedded in the soil layer on all sides, thus ensuring a good retaining action on the soil layer. In this connection, each projection is preferably at a distance from every other projection and preferably does not touch any other projection.

The cladding elements with covering layer may be situated on the side which faces the body of water, and/or on the side which faces away from the body of water. In the latter case, the covering layer also offers protection against water which swaps over the water-control structure. Usually, this leads to the unprotected covering layer, such as a soil layer, being washed away, resulting in a weakening of the water-control structure from the rear and consequently giving way. However, due to the stabilizing action of the cladding elements according to the invention, crumbling can be prevented.

Preferably, the cladding consisting of adjacent cladding elements and/or adjacent damping elements extends across the crown of the control structure body and across at least one side in an uninterrupted manner. Preferably, the cladding extends across both sides and the crown in an uninterrupted manner. Such a continuous cladding has various advantages. Firstly, such a cladding forms a skin which stabilizes the climate in the dike. As a result thereof, the control structure body is prevented from becoming too wet in the winter and too dry in the summer. This stabilizing effect is particularly important in the case of peat dikes, since the formation of cracks due to the control structure body drying out can thereby also be prevented. It is found that, in practice, problems occur mainly in the locations at the transitions in the cladding. This may affect transitions between surfaces which are arranged at different angles, such as from oblique to horizontal, with stepped transitions and the like. Due to the locally higher flow rates, these transitions may suffer from weakening phenomena. By means of a continuous cladding consisting of closely adjoining cladding elements, such phenomena can be prevented. The cladding element may be configured in different ways. For example, the base may have an approximately substantially square periphery. Also, the sides of the base may be convexly curved and adjoin one another via an obtuse internal angle. In other words, the cladding element has a basic shape which is square, with the sides of the base being slightly convexly curved to the outside. Due to these slightly convexly shaped sides, adjacent cladding elements only contact one another to a limited degree and mutually enclose open spaces. As has already been mentioned, these open spaces may contain gravel or hard core which promotes the mutual retaining action of the cladding elements. Such a series of adjacent cladding elements has an acceptable percentage of open spaces, so that no great water pressures can occur underneath the cladding.

In a further advantageous embodiment, the sides of the base are directed obliquely towards one another, in an upward direction. For example, the cross section of the base in the upward direction may decrease monotonously up to and including the attachment of the projection at the base. Hard core can be dumped in the gaps which are thus created between the bases of the cladding elements, and exert a clamping action and consequently a retaining action on the cladding elements.

The projection may have different shapes; thus, the cross section of the projection may be circular. Alternatively, the cross section of the projection may be approximately square, but other shapes, such as triangular, are also possible. Furthermore, the surface of the cross section of the projection may decrease in the upward direction. As a result thereof, the soil layer can penetrate well up to and around the cladding elements. In this connection, the surface of the top of the projection may be smaller than any cross section of the projection; optionally, the cross section of the projection in the upward direction may decrease monotonously up to and including the top.

The above-described water-control structure offers a multiple, fail-safe protection. This is the result of the construction which consists of, successively, the cladding elements, the soil layer dumped on top thereof and the grass layer, which together form a continuous top layer. This top layer provides the desired water-control properties. However, if the grass layer were to be washed away for some reason, followed by the soil layer, the layer of cladding elements still offers stable protection. As a result thereof, the control structure body remains protected against attacks by water sweeping over the dike.

Finally, the invention relates to a cladding element for a water-control structure as described above, comprising a base and one and only one projection which is upright with respect to the base, wherein the surface of the cross section of the projection decreases in the upward direction up to the top of the projection. Such a cladding element is preferably made of concrete. The shape of the cladding element is preferably detachable, that is to say that the cladding element which is produced in a mould can be removed from said mould in one piece. This can be achieved if the cross section of the projection decreases monotonously from the base in the upward direction up to the top of the projection. The base itself may likewise have such a detachable shape.

The invention will now be explained in more detail by means of exemplary embodiments which are illustrated in the figures, in which:

FIG. 1 shows a longitudinal section through a dike.

FIG. 2 shows an enlarged view of the longitudinal section from FIG. 1.

FIG. 3 shows a perspective view of a section of the dike with the soil layer partly removed.

FIG. 4 shows a first variant of the cladding elements in perspective.

FIG. 5 shows a second variant of the cladding elements in perspective.

FIG. 6 shows a second embodiment of a dike.

FIG. 7 shows a third embodiment of a dike.

The water-control structure illustrated in FIGS. 1 and 2 consists of the control structure body 1, made of for example sand, clay and the like, and the cladding 2. This cladding 2 in turn consists of the cladding elements 3, as illustrated on a larger scale in FIG. 2, with the soil layer 4 on top. This soil layer may be covered with grass 5. The water-control structure has a side 10 which faces a body of water 12 and a side 11 which faces away from the latter.

The cladding elements 3 each consist of a base 6 and a projection 7 which is vertical with respect to the base, as is also shown in perspective in FIGS. 3 and 4. The projection 7 has smaller cross sections than the base 6; as a result of which there is a leap in the cross sections of the cladding element 3 at the transition between the projection and the base. In the embodiment of these FIGS. 3 and 4, the projection 7 has circular cross sections whose radius becomes increasingly smaller from the base 6. As a result thereof, the soil layer 4 can readily penetrate as far as between the projections 7. The roots 19 of the grass 5 could also penetrate between the projections 7 and also between the bases 6 of the cladding elements 3 as far as into the control structure body 1, which is advantageous for the stability of the cladding 2. In the variant from FIG. 4, the projections 7 have circular cross sections. The gaps between the cladding elements taper upwardly, although this cannot be seen in FIGS. 3-5.

The base 6 of the cladding elements 3 may have sides 8 which are curved slightly convexly, so that gaps 9 between adjacent sides 8 of neighbouring cladding elements 3 are prevented. Furthermore, the sides may recede slightly in the upward direction, so that the gaps between the sides 8 of neighbouring cladding elements 3 taper downwardly in the shape of a wedge. By introducing hard core 13 in the form of fine granular material into these gaps, the stability of the cladding layer is greatly improved due to mutual clamping of the cladding elements. In addition, the water-permeability is maintained due to the gaps, so that a build-up of pressure from water behind the cladding elements is prevented or limited. This also has an advantageous effect on the stability of the layer of cladding elements 3.

FIG. 6 shows a further possible embodiment of a dike, in which cladding 2 comprising cladding elements 3 with a soil layer 4 on top is only present on the side facing the body of water 12. This cladding 2 is only provided in the area which is influenced by the body of water 12. The other parts of the dike are constructed in a traditional style.

FIG. 7 shows a dike which is provided with the cladding elements 6 according to the invention on the side 11 facing away from the body of water. These cladding elements retain the soil layer 4, even if water were to pour over the dike. On the side 10 facing the body of water damping elements 15 are provided, each consisting of a base 6, a neck 16 and a head 17. These damping elements 15 are suitable for damping the waves to which the dike is exposed. The water which strikes the side 10 of the dike is tempered in the damping spaces 14 which are situated between the heads 17 and necks 16 of the damping elements 15.

LIST OF REFERENCE NUMERALS

-   1. Control structure body -   2. Cladding -   3. Cladding element -   4. Soil layer -   5. Grass layer -   6. Base -   7. Projection -   8. Side -   9. Gap -   10. Side -   11. Side -   12. Body of water -   13. Hard core -   14. Damping space -   15. Damping element -   16. Neck -   17. Head -   18. Crown -   19. Root 

1. Water-control structure, comprising a control structure body (1) which is exposed, at least on one side (10, 11), to the effects of a body of water (12), and adjacent cladding elements (3) which cover the control structure body (1) and which each comprise a base (6), and adjacent bases (6) of the cladding elements (3) between themselves define passages for allowing water through, wherein the cladding elements (3) are covered by a covering layer (5) which is provided between and above the projections (7).
 2. Water-control structure according to claim 1, wherein the cladding elements (3) have one and only one free projection (7) which is upright with respect to the base (6).
 3. Water-control structure according to claim 1, wherein a side (10) which is provided with cladding elements (3) faces the body of water (12).
 4. Water-control structure according to claim 1, wherein a side (11) which is provided with cladding elements (3) faces away from the body of water (12).
 5. Water-control structure according to claim 1, wherein the base (6) has an approximately substantially square periphery.
 6. Water-control structure according to claim 1, wherein the sides (8) of the base (6) are convexly curved and adjoin one another via an obtuse internal angle.
 7. Water-control structure according to claim 1, wherein the sides (8) of the base (6) are directed obliquely towards one another, in an upward direction.
 8. Water-control structure according to claim 1, wherein the cross section of the projection (7) is circular.
 9. Water-control structure according to claim 1, wherein the cross section of the projection (7) is approximately square.
 10. Water-control structure according to claim 1, wherein the surface of the cross section of the projection (7) decreases in the upward direction.
 11. Water-control structure according to claim 1, wherein the surface of the top of the projection (7) is smaller than the cross section of the projection which adjoins the base (6) and is preferably smaller than any cross section of the projection.
 12. Water-control structure according to claim 1, wherein the cross section of the projection (7) decreases monotonously in the upward direction up to and including the top.
 13. Water-control structure according to claim 1, wherein the cross section of the base (6) decreases monotonously in the upward direction up to and including the attachment of the projection (7) at the base.
 14. Water-control structure according to claim 1, wherein each projection (7) is situated at a distance from every other projection (7) and does not touch any other projection (7).
 15. Water-control structure according to claim 1, wherein projections (7) are each embedded in the covering layer (5) around the entire periphery thereof.
 16. Water-control structure according to claim 1, wherein the control structure body (1) has a side (10) which faces the body of water (12) and a side (11) which faces away from the body of water.
 17. Water-control structure according to claim 16, wherein the side (11) facing away from the body of water (12) is provided with the cladding elements (3) and the side (10) facing the body of water is provided with damping elements (15).
 18. Water-control structure according to claim 1, wherein the control structure body (1) is covered with cladding (2) consisting of adjacent cladding elements (3) and/or adjacent damping elements (15), which cladding (2) extends across the crown (18) of the control structure body (1) and at least one side (10, 11) in an uninterrupted manner.
 19. Water-control structure according to claim 18, wherein a side (10) which is provided with cladding elements (3) faces the body of water (12), another side (11) which is provided with cladding elements (3) faces away from the body of water, and the cladding (2) from adjacent cladding elements (3) and/or adjacent damping elements (15) extends across the crown (18) and both sides (10, 11) in an uninterrupted manner.
 20. Cladding element (3) for a water-control structure according to claim 1, comprising a base (6) and one and only one projection (7) which is upright with respect to the base, wherein the surface of any cross section of the projection is smaller than any cross section of the base (6).
 21. Cladding element according to claim 19, wherein the cross section of the projection (7) which adjoins the top of the projection and/or the surface of the top of the projection is smaller than the cross section of the projection (7) which adjoins the base (6). 